Personalized Three Chemistry Rocks Toddler Full Zip Hooded Jacket. Chemistry Rocks text with three dancing rocks is a humorous chemistry gift design for back to school, birthdays, holidays and graduation. 7.5 oz., 60/40 cotton/polyester. Jersey-lined double-needle hemmed hood. Pouch pockets for all their treasures. Coverstitched shoulders and armholes. Coverstitched rib waistband and cuffs.